石英砂滤料表面干法改性制备疏水性除油滤料

采用钛酸酯偶联剂DN101对石英砂滤料进行表面干法改性,增强滤料的亲油疏水性。通过单因素实验研究改性时间、DN101浓度以及改性温度对改性效果的影响,并以亲油亲水比LHR作为评判改性效果的标准。结果表明,反应时间为70 min、DN101用量为1.2%、反应温度为60℃时,DN101干法改性石英砂效果最好,LHR值由未改性时的1.25提高到最大值11.1;改性石英砂对15.61 mg·L^-1含油废水的吸附容量由未改性时的0.17 mg·g^-1增大到0.25 mg·g^-1;对17.3 mg·L^-1含油废水的过滤去除率由未改性时的72.6%提高到97.8%。扫描电镜、电子能谱和红外光谱分析结果表明,DN101以化学键的方式与石英砂表面官能团结合,对石英砂形成了均匀稳定的包覆层。     

石英砂滤料表面干法改性制备疏水性除油滤料

采用钛酸酯偶联剂DN101对石英砂滤料进行表面干法改性,增强滤料的亲油疏水性。通过单因素实验研究改性时间、DN101浓度以及改性温度对改性效果的影响,并以亲油亲水比LHR作为评判改性效果的标准。结果表明,反应时间为70 min、DN101用量为1.2%、反应温度为60℃时,DN101干法改性石英砂效果最好,LHR值由未改性时的1.25提高到最大值11.1;改性石英砂对15.61 mg·L~(~(-1))含油废水的吸附容量由未改性时的0.17mg·g~(-1)增大到0.25 mg·g~(-1);对17.3 mg·L~(-1)含油废水的过滤去除率由未改性时的72.6%提高到97.8%。扫描电镜、电子能谱和红外光谱分析结果表明,DN101以化学键的方式与石英砂表面官能团结合,对石英砂形成了均匀稳定的包覆层。     

毛细上升法研究水处理滤料的表面热力学特性

基于Washburn方程用亲油亲水比(LHR)比较了0.9～1.2 mm无烟煤、锰砂和石英砂滤料的润湿性; 同时以正己烷、1-溴萘、甲酰胺和去离子水为探针液, 用Washburn方程和van Oss-Chaudhurry-Good(vCG)理论对滤料表面自由能成分进行了估算。实验测得无烟煤、锰砂和石英砂的LHR值依次为1.93、0.75和0.69, 说明无烟煤的亲油性较好而锰砂和石英砂表现出了亲水性; 估得无烟煤、锰砂和石英砂滤料的表面自由能非极性成分和极性成分依次为38.8、38.0、37.7 mJ·m-2和0.73、6.8、8.7 mJ·m-2,初步说明水处理滤料的表面润湿性与其表面自由能极性成分γABs之间有一定的相关性; 而后者归因于滤料的表面化学组成。     

水处理滤料润湿性能测定方法的比较研究

根据Washburn方程,采用高度法和压力法测量滤料接触角,引入亲油亲水比(RLH)的概念,以正辛醇和去离子水作参比液,得出了25℃下核桃壳和石英砂滤料的亲水亲油比值。结果表明,压力法更适合滤料接触角测量,核桃壳颗粒对于非极性液体的润湿性较好,石英砂对于极性液体的润湿性较好,本研究为含油废水处理滤料的润湿性能改进提供一种新思路。     

新型聚丙烯酸酯乳液对纳米氢氧化镁的改性研究

为使纳米氢氧化镁的表面性质由亲水性变为亲油性,以使其在高聚材料中能够更好地分散填充并减少团聚,采用新型纳米聚丙烯酸酯乳液作为改性剂,对纳米氢氧化镁进行了表面改性研究。采用活化指数测试、接触角测试、红外光谱分析及热重分析等手段研究了改性纳米氢氧化镁的结构和性能。结果表明,在改性剂添加量（改性剂与纳米氢氧化镁的质量比）为0.6时,纳米氢氧化镁的表面性质由亲水疏油转变为亲油疏水,新型纳米聚丙烯酸酯乳液与纳米氢氧化镁粒子表面发生了化学反应,并包覆在其表面,达到了较好的改性效果。对比了其他传统型硅烷偶联剂对纳米氢氧化镁的改性效果,结果表明新型聚丙烯酸酯微乳液改性的纳米氢氧化镁的分散性和疏水亲油性都要优于传统型硅烷偶联剂的改性效果。     

钛酸酯偶联剂对石粉无机废料的表面改性工艺研究

研究了钛酸酯偶联剂对石粉无机废料的改性效果,利用复合改性工艺探索钛酸酯偶联剂用量对石粉无机废料的亲油性、吸油值和活化度的影响,外光谱分析改性效果。得出改性后的石粉废料亲油性较好,吸油值较低,活化度达到91.60%,且废料表面有效键合了其他有机化学键。     

改性石英砂强化火电厂中水回用微污染物处理效果研究

通过对石英砂滤料的改性研究改变原滤料表面物理化学性质,提高滤料吸附能力和截污能力,强化对中水中有机物的去除效率。分别试验了对石英砂进行铝盐和铁盐方法的改性,过对比了静态吸附试验和动态过滤试验改性石英砂和未改性石英砂对微污染水中有机物和浊度的去除效果。结果表明,改性砂对COD和浊度的吸附效果较之未改性前均有明显提高,COD去除率由5%提高到20%～30%,浊度的去除率由37%提高到55%～65%,动态试验与静态试验结果一致,去除率也均有提高;不同金属氧化物的改性砂性能不同。     

GO-PTFE复合膜强化膜蒸馏深度处理焦化废水

为了提高膜的抗污染抗润湿性能,采用表面涂覆法将氧化石墨烯(GO)结合在聚四氟乙烯(PTFE)膜表面,制备亲水-疏水复合膜用于膜蒸馏深度处理焦化废水,并对比了改性复合膜与未改性原膜的表面特性和膜蒸馏效果,分析了GO表面改性对膜蒸馏效果的强化机制。结果表明,膜表面经过GO改性后接触角由144.2°下降至103.9°,且表面出现羟基、羧基等亲水性官能团,说明膜表面亲水改性成功。GO-PTFE复合膜相比原膜通量提高了36.6%,产水电导率保持在25μS/cm,出水的荧光峰强度明显减弱,说明GO-PTFE复合膜能有效截留焦化废水中的无机盐和有机物,相比原膜的抗污染抗润湿性能显著提高。这种强化过程主要归因于GO良好的亲水性、导热性和特有的纳米孔道对污染物的截留效应。     

超分散剂对重质碳酸钙的两亲性改性研究

采用聚酯型两亲超分散剂对超细重质碳酸钙填料进行表面改性。借助傅里叶红外光谱、旋转黏度仪、激光粒度仪和电子扫描电镜等对碳酸钙的改性效果进行了分析表征。结果表明:聚酯型两亲超分散剂对重质碳酸钙的改性效果良好,与未改性的碳酸钙相比,改性后的碳酸钙粒径分布变窄,吸油值降低,改性碳酸钙与液体石蜡的相容性好,在聚乙烯和水中都能均匀分散,体现了良好的亲油亲水性能。     

医用硅橡胶导管的表面改性及其亲水性和抗菌性研究

对硅橡胶导管进行表面改性,制备具有亲水和抗菌功能的医用硅橡胶导管,并对其性能进行表征。结果表明:与未改性导管相比,改性导管的摩擦系数减小90%以上,亲水性明显改善;水浸泡7 d后改性导管仍具有较好的润滑性,且涂层与导管表面的粘合性较好;改性导管对金黄色葡萄球菌具有良好且持久的抗菌性,能满足临床应用要求,具有良好的应用前景。     

Variations of Surface Tension with Body and Surface Concentrations

Mathematical derivatives of surface tension with body concentration and with surface concentration are examined analytically for solutions in which the activity coefficient of the solute is taken as a linear function of solute concentration in the body, and as fixed at unity in the surface. As an approximation, the surface concentration is taken as a uniform value maintained throughout a surface domain extending from the geometrical surface to a fixed depth into the solution, at which the concentration changes as a step function to the body concentration. The writer accepts previous experimental and theoretical conclusions that for an ionic solute the increment of surface tension per surface ion increases with decreasing ionic radius. The Debye-Hückel equation for the activity coefficient of electrolytes predicts that the activity coefficient of an ionic solute increases with increasing ionic radius. Experimentally, this predicted dependence and its reverse are observed about equally often. For those solutes which behave according to the Debye-Hückel prediction it is found that a negative derivative must exist between the derivatives of surface tension with body and with surface concentration at sufficiently high values of the increment of surface tension per surface ion.     

Catalytic Aluminas: Surface Models and Characterization of Surface Sites

Aluminas have been used extensively as adsorbenu and active catalysrs and catalyst supponsm the pas. Already in 1197 the aluminadyzed dehydration of ettllnoi was dtscavered by Dutch chermsts: and S;rbatier [3] remewed the use of dumlnas as active cazaiysrs far vanous reacttons UI the second decade of thu century. She that time the applicazions of aluuuas m dycic pmcesses have mcreased tremendously. In tndustrral cualytic pmcesses, alumuus are mostiy used as catalyst suppons [4]. Oxides a d mued oxides ap well as tracuuion mauls and noble meare supported oa alumma. Thuscb. romaa-elumana catalysts are ktng used for the conversion of parafdns to olailnrc hydrocarbons, 10 hydrodealkplation of aromatics. and to a lesser exzm in catalyzic reforming. The larter process LS also caralyzed by molybdena-alumina, a cavlyst system whid is also active for malang toluene and ocher aromatics from satwed hydrocarc bons. It also dyzes the Isomerhation of pm. Great efions are presently be-made to nudy the surface chemlstry of these molybdena-alumma ysfs [5, 6]. The great mterest LD. ttuS catalyst and its detailed nature and properties are certadp reiated to the enormous imnortance of cobalt oxade-molybdenum omde-nlumlna as a widely u5ed Caulytic system for hydrodesuUunzaim, hydmdeoirrogemion, and hydmcracklng reacttans. Cenaialy one of the most imporrant appllcations of alumbas is its use as a support for nobie met tn cazalpzic reformtng, My, dunsinas may also be used as supports for the immobilt.? tioa of mommuclear complexes and of polynucieu me clusters, a fleld which hs recently begun to attraa the Wrest of cacaiytic chamlsts [7, 8].     

Catalytic Aluminas: Surface Models and Characterization of Surface Sites

Abstract

In recent years polyurethanes have been confronted with several challenges. Some of these challenges have been overcome with the development of new catalysts. This review article covers recent developments in the field of polyurethane catalysis. An overview of the different types of catalysts, their applications, and their actuation mechanisms, followed by a general survey of the stability of one‐component polyurethane systems in which the latent catalyst is already incorporated is presented.     

Surface and interfacial chemistry

Based on a molecular approach combining controlled surface chemistry, advanced spectroscopic methods, in particular solid-state NMR, and computational chemistry, it is possible to develop single-site species and to control the growth of nanoparticles on supports. This allows the generation of highly efficient catalysts combining the advantages of both homogeneous and heterogeneous catalysts and function materials with defined properties.     

Surface chemistry and adhesion

Adhesion science is still a controversial area of research; no universal theory of adhesion exists and the actual mechanism of adhesion operating across many industrially important interfaces is still unresolved. In this review wetting processes and methods for estimating the surface free energy of polymers from contact-angle measurements are discussed. Emphasis is placed on the relationship between the work of adhesion estimated from surface free energies of solids and the measured adhesive joint strength.     

铝及铝合金表面处理后的表面特征和粘接特性

本文介绍了铝材表面处理的目的与要求、经过各种机械和（电）化学方法处理后的表面特性,如表面形貌、表面粗造度、表面化学组成、表面润湿特性、表面氧化物的环境稳定性及其粘度接特性。其中以磷酸阳极化作最后表面处理工序获得的效果最好,在此前的化学处理工序基本不影响最后表面处理效果。     

Unifying Solution and Surface Electrochemistry: Limitations and Opportunities in Surface Electrocatalysis

The electrochemical transformations involving small molecules could play a key role in energy storage and utilization. In this work, we develop a link between surface and solution electrochemistry and this is accomplished by relating the correlated binding of hydrogenated species on metal surfaces to their formation energy in solution. This link provides a semi-quantitative treatment of the thermodynamic landscape of multi-electron electrochemical reactions. Using this simple analysis, we identify some of the fundamental limits of oxygen, nitrogen and carbon electrochemistry. This analysis points to new avenues of electrocatalyst design and two such avenues are discussed in detail.     

Surface Energetics and Adhesion

The relationships between surface energetics and adhesion are critically reviewed. New data that confirm such relationships, for peel tests as well as lap shear tests, are presented. The effect of hydrothermal aging of aluminum surfaces on surface energetics can be used to predict degradation in bond strength. The mechanism of failure for elastic adhesives (such as Scotch ® tape) in peel tests may be essentially the same as for more brittle adhesives (such as epoxies) in lap shear tests. This mechanism may involve brittle fracture that forms a critical flaw at the adherend-adhesive interface (on a microscopic level), followed by crack propagation which then may include considerable elastic and plastic deformation. The locus of propagation (fractography) is generally not (but may be) relevant to the problem of how to remedy mechanical weakness in an adhesive joint, since the local region of critical flaw formation rather than the general surface area determines the joint strength.     

Adhesion and Surface Analysis

In the last 25 years, surface sensitive analytical techniques have made a major contribution to our understanding of adhesion phenomena and problems. There are several areas where these techniques have provided important information including the identification of failure modes, the chemistry of a substrate before and after pretreatments, the stability of surfaces and interfaces, the identification of surface contaminants, the interaction across an interface and the nature of interphases. X-ray photoelectron spectroscopy (XPS or ESCA), Auger electron spectroscopy (AES) and static secondary ion mass spectrometry (SSIMS) have proved to be especially useful. Many examples of the usefulness of these techniques are given.